The invention relates to a compound capable of introducing at least one molecule into a cell.
The invention also relates to a positively charged vesicle whose membrane comprises this compound, to a vector containing at least one molecular combined with the vesicle according to the invention; to the cell, animal and/or plant transformed by said compound or said vector as well as to the pharmaceutical or cosmetic composition, comprising said vector and/or the cell transformed by said vector.
The invention also relates to the process for the synthesis of said compound and to the process for the production of said vector.
Another aspect of the invention relates to the use of the compound and/or vector for the introduction in vitro and/or in vivo of at least one molecule into a cell.
Various processes are used in genetic engineering and/or in pharmacy to introduce molecules such as nucleic acids or active therapeutic agents into cells.
Transfection is a method which is widely used for introducing genetic material into cells, for studying the expression of genes, and for developing strategies for gene therapy.
Numerous experimental procedures using physical modifications (microinjection, electroporation and the like) or chemical modifications (dextran phosphate, calcium phosphate and the like) of membranes have been developed with varying success for introducing nucleic acids into cells using this method.
Another axis of research relates to the development of new amphiphilic cationic vectors which have demonstrated their effectiveness and their ease of use for causing the genetic material to penetrate into cells in vitro (P. L. Felgner et al., Proc. Natl. Acad. Sci., USA, 84, pp. 7413-7417 (1987)).
Some of these vectors such as the Lipofectin(copyright) N-(2,3-dioleyloxy)propyl-N,N,N-trimethylammonium chloride (DOTMA) from GIBCO BRL or the Transfection-reagent(copyright) N-(2,3-dioleoyloxy)propyl-N,N,N-trimethylammonium methyl sulfate (DOTAP) from Boehringer Mannheim GmbH, have been commercialized.
Patent Application WO91/15501 (YALE UNIVERSITY) also describes a positively charged reagent consisting of a neutral phospholipid such as dioleoylphosphatidylethanolamine and a cationic lipid such as stearylamine, a tertiary amine or a benzothorium salt for the transfection of nucleic acids.
Nevertheless, these products require large quantities of reagents in order to obtain an effective transfection of cells and therefore increase the cytotoxicity of the products and their costs (thus, the price of the xe2x80x9cLipofectin(copyright)xe2x80x9d product (DOTMA) in U.S.$ 145/ml, equivalent to U.S. $10 per transfection).
In addition, Lipofectin(copyright) (DOTMA) has the additional disadvantage of not being capable of being added to a serum.
The document xe2x80x9cVesicle Formation by double long-chain Amidinesxe2x80x9d (Fabienne Defrise-Quertain et al.) (J. Chem. Soc., Chem. Commun., 1986, p. 1060 to 1062) describes the formation of vesicles consisting of 3-tetradecylamino-N-tert-butyl-Nxe2x80x2-tetradecylpropionamidine.
However, this document does not contain sufficient description for the preparation of these compounds. Indeed, this document does not indicate the reaction temperatures to be used or the fact that it is necessary to use a basic aqueous solution in order to form the compound of formula 
in which OR is the residue of an alcohol of formula ROH and R2 is selected from the group consisting of hydrogen atom, saturated alkyl chains, unsaturated alkyl chains and substituted alkyl chains; an intermediate compound which is necessary for the production of the compounds according to the invention.
The aim of the present invention is to produce a new compound and/or a new vector capable of introducing at least one molecule into a cell, without exhibiting the disadvantages of the prior state of the art.
The invention is also intended for producing a pharmaceutical or cosmetic composition comprising said vector and/or said cell transformed by said vector.
An additional aim of the present invention is intended for producing a vector which can be used in a serum.
The present invention relates to a compound of the general formula: 
in which:
A is selected from the group consisting of the radicals comprising a hydrophilic group or a CH2 group and a hydrophobic group;
n is a positive integer (1 less than n less than 10; more preferably n=2); and
R2, R3 and R4 are selected from the group consisting of a hydrogen atom, saturated alkyl chains, unsaturated alkyl chains and substituted alkyl chains.
Preferably, A represents a radical or residue of formula:
R1xe2x80x94Xxe2x80x94
in which
R1 is selected from the group consisting of a hydrogen atom, saturated alkyl chains, unsaturated alkyl chains and substituted alkyl chains, and
X represents a divalent atom or a divalent group of atoms.
R1xe2x80x94X represents a residue selected from the group consisting of: 
Preferred compounds according to the invention are the nitrogen derivatives above-described.
Advantageously, R1 and R3 or R1 and R4 are selected from the group consisting of hydrocarbon chains containing 2 or more carbon atoms, preferably 12, 14, 16 or 18 carbon atoms chains.
According to a preferred embodiment of the invention, the compound according to the invention corresponds to the following formula: 
in which 12xe2x89xa6mxe2x89xa618 (m=12, 14, 16 or 18), and X represents the divalent atoms or divalent groups of atoms above-described.
According to another preferred embodiment of the present invention, the compound according to the invention has the following formula: 
wherein m=12, 14, 16 or 18.
The invention also relates to a positively charged vehicle having a membrane comprising a compound according to the invention as well as a vector consisting of said vesicle associated with at least one molecule to be introduced into a cell, said molecule being advantageously selected from the group consisting of nucleic acids (nucleic acids oligomers or nucleic polymers), antigens, polypeptides or optionally glycosylated proteins and/or active therapeutic or cosmetic agents.
Said molecule is introduced in a cell by a process wherein said cell is brought into contact with said molecule and a compound and/or a vesicle according to the invention. Likewise, the introduction process can be achieved by bringing said cell into contact with a vector according to the invention.
A xe2x80x9cnucleic acid according to the inventionxe2x80x9d means any kind of nucleic acids polymer of oligomer such as a plasmid, messenger RNAs, antisense RNAs, cDNAs, synthetic oligonucleotides and the like which are capable of genetically transforming a cell and which may express a specific antigen, polypeptide or protein as well as an active therapeutic or cosmetic agent into said cell.
According to a first embodiment of the process of the invention, a cell is treated in vitro in order to produce plants or animals which are transgenic or for gene therapy, in particular for the treatment of cellular disorders such as cancer or infections such as viral or bacterial infections or the like.
According to the second preferred embodiment of the process of the invention, a cell is treated in vivo in order to produce recombinant microorganisms, plants and/or animals which are transgenic or in for ex vivo or in vivo gene therapy.
Another aspect of the invention concerns a new composition comprising a molecule to compact DNA, preferably a protamine, a polylysine or a histone derived peptide, and the compound, the vesicle or the vector according to the invention.
The composition according to the invention may also comprise another compound which increases cell endocytosis, preferably a microtubule inhibitor.
Another aspect of the present invention is related to a transfection kit comprising said composition, compound(s), vesicle or vector according to the invention, for the transfection of cells, plants or animals.
The present invention also relates to the cell, the animal or the plant transformed by the vector according to the invention as well as a cosmetic or pharmaceutical (such as a vaccine) comprising the vector and/or the transformed cell according to the invention.
Another aspect of the present invention relates to the process for the synthesis of the compound in which compounds of formula CH2xe2x95x90CHCxe2x95x90N and R2xe2x80x94Cl are reacted with anhydrous ferric chloride so as to form the tetrachloroferrate of a compound of formula CH2xe2x95x90CHCxe2x95x90N+xe2x80x94R2, this tetrachloroferrate is treated with an amine of formula R3xe2x80x94NHxe2x80x94R4 so as to form a compound of formula: 
The invention also relates to a process for the production of the vector according to the invention in which at least one molecule selected from the group consisting of nucleic acids molecules, antigen molecules, polypeptides, glycosylated polypeptides, proteins, glycosylated proteins, therapeutic agents and cosmetic agents are reacted with a vesicle according to the invention.
A final aspect of the present invention relates to the use of the vector and/or the compound according to the invention for the introduction of one or more molecules into a cell in vitro as well as the use of the vector according to the invention for the introduction of one or more molecules into a cell in vivo.